Photographic printing machine



Feb. '14, 1939. H O DRQTMM; 2,146,886

PHOTOGRAPHIC PRINTING MACHINE Filed Nov. 13/ 19s? m IIII-IIII ATTORNEiS Patented Feb. 14, 1939 UNITED STATES PATENT OFF-ICE.

PHOTO QRAPHIC PRINTING MACHINE Henry 0. Drotning, Rochester, N. Y., asslgnor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application November 13, 1937, ,Serial No. 174,423

4 Claims. (Cl. 95-73) This invention relates to photography and more particularly to platens for photographic printing machines.

One object of my invention is to provide a platen by which a sheet of paper or film may be held into intimate contact with a negative at spaced intervals over its surface. Another obiect of my invention is to provide a platen with a plurality of resilient fingers which may be differentially compressed in accordance with varying thicknesses of materials, such as printing masks and the like. Still another object of my invention is to provide a platen in which a plurality of resilient fingers are spaced apart in spaced relation with a plurality of orifices, so that any individual protuberance may flex into its corre- I sponding orifice, thereby tending to permit the useof irregular surfaces and at the sametime retain printing contact between photographic paper and a negative. Other objects will appear from the following specification, the novel features being particularly pointed out in the claims at the end thereof.

In printing machines, and particularly in printing machines of the larger commercial sizes, even when the best grade of plate glass is used for the printing panels, it is diillcult to secure uniform and even'pressure over the entire printing area. It is customary to use printing masks of varying thicknesses over parts of the negative and to lay the printing paper over the top of the 'masks. It istherefore desirable toprovide a series of more or less independently resilient projections or fingers for pressing the paper toward the negative over spaced areas.

The present invention is for an improvement over the platen construction shown in U. S. Patent 1,809,238, Roy S. Hopkins, granted June Coming now to the drawing wherein like reference characters denote like parts throughout:

' Fig. 1 is a fragmentary side elevation partially in section of.a printing machine with a platen constructed in accordance with and embodying a preferred form, of my invention.

Fig. 2 is an enlarged fragmentary detail section through a portion of a platen constructed in accordance with and embodying a preferred form of my invention. I

Fig. 3 is a similar view but of a modfied embodiment 'of my. invention.

Fig. 4 is a similar view of still a different modification of my invention, and Fig. 5 is a fragmentary plan view of a portion ofthe platen shown in Flgal and 2.

In Fig. l, I have schematically indicated a printing machine as consisting of a box member I having an opening 2 supporting a glass printing panel 3. I preferably provide beneath the glass printing panel, a reflector 4 in which a suit- 5 able printing lamp 5 is mounted. .With printing machines of this type, it is customary to lay the negative, which is usually a film negative, on the printing panel 3, although if a glass negative is i used of the size of the rabbet 6 which supports 10 the printing panel 3, the printing panel may be dispensed with. A platen designated broadly as I is used to hold the printing paper in intimate contact with the negative. Such a platen may consist of two'parts 8 and 9, part 8 being hinged at ill to a hinge pintle carried by a slidable bolt II and normally held in the position shown by the spring l2. Section 9 is hinged to section 8 by means of a pintle l3 and is preferably provided with a handle 14, so that platen section 8 and the platen section 9 can be. success.vely lowered to hold a sheet of paper against a negative for printing.

As thus far described, the printing machine may be of any standard or known construction- This application is particularly directed to the structure of the platen itself.

The platen sections 8 and 9 may consist of rectangular frame members 15 which are covered on their bottom surfaces with relatively rigid plates l6. As indicated in Fig. 5, the plates I6 may be provided with a plurality of apertures I! which, for convenience, are made circular in shape, as shown in this figure. The platen I5 is preferably relatively rigid, and, if desired, may be made of some transparent material, such as a suitable cellulosic composition. 0n the bottom of the plate It, I prefer to attach, as by cementing, a relatively thin sheet of soft resilient material, such as rubber. This sheet of material carries a series of protuberances which are preferably of semi-spherical shape and which are spaced in accordance with the spacings of the apertures ll. Thus, when the rubber sheet l8 has been cemented in place as indicated in Fig. 2, a. protuberance ll will lie directly beneath and preferably in axial alinement with the aperture wardly in to the aperture ll.

In Fig. 3, I show a second embodiment of my invention in which the rubber sheet I8 is profor the protuberance l9 to flex upwardly as the rubber sheet i8 is stretched at the areas marked 8.

I prefer to provide an opening 28 through which air can freely escape as the protuberance flexes into the recess 2?. If desired, an air open= ing 29 can be made through the rubber sheet, although this is not ordinarily desirable because in flexing, the aperture may tend to close.

In accordance with Fig. 4, the rigid platen mem= ber 35 may be made of a thin sheet of metal and the apertures 3'! may be drilled through the metal so as to permit the rubber sheet to flex as indicated in this figure. In this embodiment of my invention, the rubber sheet 38 is preferably thin and may be provided with p'rotuberances 39 in the shape 'of truncated cones oi smaller diameter than the apertures 81. In extreme cases, it is possible that the rubber sheet-88 will stretch to such an extent that it may project entirely through the apertures 37?.

With any of the embodiments illustrated above,

I can obtain a platen structure in which comparatively light pressure on any one or more of the protuberances will cause the material to flex upwardly-into the recesses oithe rigid platen member to such an extent that material of varying thicknesses can bereadily used for the mas members without at all disturbing the ount of pressure which is actually applied to the various is required on the handle it of the platen to ee= aieaeee cure excellent contact overiarge negative area.-

What I claim is:

i. In a printing device, the combination with a printing panel, of a platen mounted to move to and from the panel, a series of spaced apertures in the platen, a covering for the platen formed of soft resilient materiaL'resilient pro- Jections on said material and spaced to-be under the apertures in the platen, said resilient projections being of smaller size than the apertures in the piston and beingadapted to flex thereinto.

2. In a printing device, the combination with a printing panel, of a platen mounted to move to and from the panel, said platen comprising a her, said rigid member including a recess for each protuberance spaced in axial alignment therewith, each recess comprising an opening of larger size than its axially alin'ed protuberance whereby each protuberance may fiex at least partially into said recess.

ii. A platen for photographic printing machines comprising a plane sheet of rubber with protuberances thereon attached to a plane rigid member, said rigid member including a recess for each protuberance spaced in axial alignment therewith, the size of each aperture being sumcient to receive at least the major part pf the protuberance when pressure is applied to the protuberance. 

